At the risk of a more glib comment than I usually try to make: Having had my systems variously backhoed, struck by lightning, physically unplugged (backup and

At the risk of a more glib comment than I usually try to make: Having had my systems variously backhoed, struck by lightning, physically unplugged (backup and primary) by a sysadmin (cough who may have on another occasion been me not properly counting the rack I was on cough), and left without mains power for multiple weeks after an electrical fire in a substation, an outage is indeed something that can sneak up on you despite best intentions. (yes yes "distribute" "build for failure" "it's apple we should expect more" are all valid answers, but wanted to make a tongue in cheek response to your wording.)